1. Technical Field
The present disclosure relates to a power train for a hybrid vehicle, in more detail a technology for transmitting power from power sources to the driving wheels in a hybrid vehicle equipped with two or more different power sources including an internal combustion engine.
2. Related Art
Hybrid vehicles using an engine and a motor generator improve fuel efficiency of the vehicles by achieving functions of idle stop and regenerative braking, on the basis of a technology of driving the vehicles at low velocity by using power from the motor generator having relatively excellent low-velocity torque characteristics and driving the vehicles at high velocity by using power from the engine having relatively excellent high-velocity characteristics.
Further, hybrid vehicles do not produce exhaust gas from the engine when being driven only by a motor generator, which is recognized as an environmental-friendly vehicle technology having advantages of improving fuel efficiency and reducing exhaust gas.
A power split type device has been known in the field of power trains for hybrid vehicles, which is classified into a single mode way and a multiple mode way. The single mode way does not need an operational element for shift control, such as a clutch or a brake, but the efficiency decreases in a high-velocity traveling, such that fuel efficiency is low and an additional torque amplifier is required to be applied to large-sized vehicles.
On the other hand, the multiple mode way can be designed to be able to ensure efficiency in high-velocity traveling and amplify torque by itself in accordance with the configuration, such that it can be applied to medium- and large-sized vehicles.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.